1. Field of the Invention
Embodiments of the invention generally relate to methods and apparatus for determining phase fractions and/or flow rates of fluid flow.
2. Description of the Related Art
In the petroleum industry, as in many other industries, ability to monitor flow of fluids in process pipes in real time offers considerable value. Oil and gas operators measure individual water/oil/gas flow rates within an overall production flow stream containing a mixture of these three phases. This information is used to improve well production, allocate royalties, prevent corrosion based on the amount of water and determine the well's performance.
Production from gas wells can include a significant liquid content (water, hydrocarbon oil, condensate or combinations thereof). Flows with relatively high gas amounts with respect to liquid amounts (e.g., around or below 5% liquid by volume) are described as wet-gas flows and represent the high gas-volume-fraction (GVF) end of multiphase flows. Various prior flowmeters attempt to enable flow rate measurements or determinations of these high-GVF flows unsuccessfully due to factors such as low accuracy and certainty in the flow rate results. Further, prior approaches often require application of generic correlation methods to correct measurements, and complex and expensive configurations for the flowmeters.
Therefore, there exists a need for improved methods and apparatus that enable determining individual flow rates within a multiphase fluid flow. A further need exists for a flowmeter to measure wet-gas flow with improved uncertainty and accuracy.